<!DOCTYPE html>
<html lang="">

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width,initial-scale=1.0">
  <title>vuex学习</title>
  <style>
    * {
      margin: 0px;
      padding: 0px;
    }
    html,
    body,
    #app {
      height: 100%;
    }
  </style>
</head>

<body>
  <div id="app"></div>
</body>

</html>